Government 2.0, or e-Government is allowing the government to interact and communicate easily with businesses and citizens. Not only is it now easier to spread information, but if constituents have a problem, social media has paved the way for them to be known.
Instead of having to write a letter or call in to a government office, now all a constituent has to do is either write an e-mail or post something to the incumbent's web site.
Also, people can comment on certain topics and see what other people are saying about topics.
These days, politics are becoming more and more controversial, and it is important for the people to know what is going on, and social media is doing just that.
There are several types of e-Government:
Barack Obama on 16 different social networks : http://www.barackobama.com/index.php?splash=false
Charlie Christ on twitter: http://twitter.com/charliecristfl
The white house blog : http://www.whitehouse.gov/blog